Lightning can be seen in the sky over a field with wind turbines in Jacobsdorf, Germany. Photograph: Patrick Pleul/AFP/Getty Images

Around 7pm GMT, Earth's atmosphere crescendos to an electrical peak, with maximal thunderstorms rumbling around the globe. Conversely 3am GMT is the electrical trough, with few lightning forks to be seen. This "electrical heartbeat" is known as "the Carnegie curve" and was discovered during the early 20th Century, by scientists on board a ship operated by The Carnegie Institution of Washington.

The rhythm of the electrical heartbeat is linked to Earth's rotation and the way thunderstorms build. New research shows clouds dance to this rhythm.

Giles Harrison and Maarten Ambaum from the University of Reading studied clouds in Finland and Antarctica during periods of solar darkness (to minimise other factors that influence clouds such as the Sun's heat). Writing in the journal Environmental Research Letters, they show that layer cloud (the blanket of low level cloud that covers about 40% of the planet) rises an average of 4m for every 1% increase in electric current, almost shifting up to 200m in the course of an electrical "heartbeat".

So what does the electrical current do to a cloud? Weather balloon measurements show it affects the charge and "stickiness" of droplets at the base of a cloud. It influences the cloud's properties, such as how much rainfall it produces and how much heat reflects into Space. Such information will improve weather forecasts. Interesting to ponder what else jives to this electric heartbeat.